After a vDPA device reset, activate_vdpa() read avail_idx from guest
memory to pass as the vring base via VHOST_SET_VRING_BASE. However,
the guest memory still contained the stale avail_idx from the previous
session. For a 256-entry ring, this meant base=256, causing the
hardware to believe the entire RX ring was consumed with no available
buffers — RX silently stopped while TX continued to work.
QEMU handles this correctly by tracking last_avail_idx internally
(reset to 0 in virtio_reset()) and passing that value, rather than
reading from guest memory.
Fix by always passing base=0 to set_vring_base(). After a device
reset, both the guest driver and the vhost backend restart their rings
from index 0. For live migration, the correct base should come from
VHOST_GET_VRING_BASE (saved before the migration), not guest memory.
Tested with mlx5_vdpa (ConnectX-6 Dx) + Windows Server 2025 (netkvm).
Before: RX=0 after 3rd driver activation. After: full connectivity.
Signed-off-by: Max Makarov <maxpain@linux.com>
KVM_GET_MSR_INDEX_LIST does not consistently include all
guest-programmable MTRR MSRs.
During save/restore while booting, the VMM initially sets only
MSR_MTRRdefType, then guest firmware or other early boot code can
program additional MTRR state before the snapshot is taken. If those
MSRs are missing from the vCPU MSR buffer, snapshot omits part of the
guest's MTRR configuration and restore resumes with an incomplete
MTRR map.
Add the guest-programmable MTRR MSRs to the KVM MSR index list used
to build the vCPU MSR buffer so the existing snapshot/restore path
preserves the guest's MTRR state.
On-behalf-of: SAP leander.kohler@sap.com
Signed-off-by: Leander Kohler <leander.kohler@cyberus-technology.de>
Some guests update the MSI-X capability through a 32-bit write at
offset 0 instead of a 16-bit write at offset 2. Update the cached
Message Control state for that path as well so MSI-X enablement stays
in sync with the guest configuration.
Add a short comment documenting why the dword write path also updates
the cached MSI-X Message Control state.
This is important for passthrough GPUs, where MSI-X interrupts are used
during NVIDIA Fabric Manager registration. Without updating the cached
state on the dword write path, interrupt delivery can remain stale and
GPU initialization or fabric registration can fail.
Signed-off-by: Damian Barabonkov <dbctl@pm.me>
This gate behaves like a barrier, but it can be opened, meaning that
threads can be released before all threads arrived at the gate. This
lets us release waiting threads in case of an error, which will be
important for the sender side of a live migration with multiple
TCP connections.
On-behalf-of: SAP sebastian.eydam@sap.com
Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
For sending memory over multiple connections, we need a way to split up
the work. With these changes, we can chop a memory table into same-sized
chunks for transmit
On-behalf-of: SAP sebastian.eydam@sap.com
Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
Adds the functionality to accept multiple connections on the receiver
side of a live migration. A thread listens for incoming connections and
creates a worker for each new connection.
On-behalf-of: SAP sebastian.eydam@sap.com
Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
With this, the receiver side of a migration can wait for incoming
connections, while also being able to abort the accept when the
migration is done.
On-behalf-of: SAP sebastian.eydam@sap.com
Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
That way we avoid having to grab a lock when receiving a chunk of memory
over the migration socket. This is a necessary prerequisite for having
multiple memory receiving threads.
On-behalf-of: SAP sebastian.eydam@sap.com
Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
The memory manager is guarded by a mutex, thus parallel accesses to it
and its members are not possible. But we have to execute this function
in parallel when we introduce multiple TCP connections. Otherwise, the
workers who receive the data and write it into guest memory will block
on each other, and thus slow down the migration.
Also rename the function to receive_memory_ranges for better naming
consistency.
On-behalf-of: SAP sebastian.eydam@sap.com
Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
When doing a local migration using a UNIX socket, we removed the UNIX
socket file after accepting the connection. The VMM does not own this
socket file, which makes this an unsafe operation. Thus, we stop doing
that.
On-behalf-of: SAP sebastian.eydam@sap.com
Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
Remove the local remote_command() function from
performance_tests.rs. The identical function is now
available from test_infra via the existing glob import.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Move remote_command() and remote_command_w_output() from
tests/common/utils.rs into test_infra/src/lib.rs to allow
reuse across crates.
The cloud-hypervisor integration tests already use
'use test_infra::*', so the functions are available
without any caller changes.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Remove the local x86_64 FOCAL_IMAGE_NAME constant from
performance_tests.rs. The identical public constant from
test_infra is already available via wildcard import.
The aarch64 definition is kept as it differs from test_infra:
performance-metrics uses a specific image with the
'-update-tool' suffix.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Remove the local DIRECT_KERNEL_BOOT_CMDLINE constant from
performance_tests.rs. The identical public constant from
test_infra is already available via wildcard import.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Remove the local direct_kernel_boot_path() function and unused
PathBuf import from performance_tests.rs. The identical public
function from test_infra is already available via wildcard
import.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Virtio v1.2 says that if CONFIG_WCE is negotiated
but FLUSH is not, the device must initialize writeback to 0.
It also says that if CONFIG_WCE was not negotiated but FLUSH
was, the driver should assume presence of a writeback cache.
Introduce a pure is_writeback_enabled helper and a
set_writeback_mode helper. This makes the two call flows
explicit:
* write_config resolves the guest requested mode against the
negotiated features before storing it back
* activate starts from the default writeback preference and then
resolves it against the negotiated features
* reset restores the initial writeback state
This keeps the config space value and the runtime writeback flag
in sync and makes the spec driven fallback easier to follow.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Refactor PciDevice::allocate_bars trait and all implementations
to take &mut SystemAllocator instead of &Arc<Mutex<SystemAllocator>>,
removing double indirection.
The caller in device_manager.rs now acquires the lock before
calling allocate_bars.
Signed-off-by: Chinmoy <daschinmoyy21@gmail.com>
The control queue handler passed the total length of all
descriptors (header + data + status) as used_len to add_used.
Per virtio spec section 2.6.8, used_len must only count bytes
written to device-writable descriptors. The device only writes
the 1-byte status/ack field.
Windows NetKVM >= 0.1.285 strictly checks this value and calls
NdisMRemoveMiniport when len != sizeof(virtio_net_ctrl_ack),
removing the network adapter immediately after activation.
Signed-off-by: CMGS <ilskdw@gmail.com>
Windows NetKVM driver (>= 0.1.271) issues unsupported command classes
even when they are not even advertised.
According to the Virtio 1.2 specification:
RX, VLAN, and ANNOUNCE control paths are only meaningful when their
corresponding features are negotiated in sections 5.1.3.1, 5.1.6.5.1.2,
5.1.6.5.2.2, and 5.1.6.5.4.1.
RX and VLAN are explicitly described as best-effort in sections
5.1.6.5.1 and 5.1.6.5.3.
Instead of returning an error to the guest, return success to the guest.
Fixes: #7925
Signed-off-by: Wei Liu <liuwe@microsoft.com>
Change the return type of RawFileAsyncAio::new() from
std::io::Result<Self> to BlockResult<Self>, wrapping
internal errors from EventFd::new() and IoContext::new()
in BlockError with DiskFileError::NewAsyncIo.
This simplifies the caller in AsyncDiskFile::new_async_io()
which no longer needs its own error mapping.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Remove the old async_io::DiskFile trait implementation from
RawFileDiskAio, now that the new disk_file trait hierarchy
is fully implemented.
Clean up unused imports: DiskFile and DiskFileResult from
crate::async_io.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::AsyncDiskFile trait implementation for
RawFileDiskAio with try_clone() and new_async_io() methods.
try_clone() duplicates the underlying file descriptor and
wraps it in a new RawFileDiskAio. new_async_io() creates a
RawFileAsyncAio (Linux AIO) backend, wrapping errors in
BlockError instead of DiskFileError.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add empty disk_file::DiskFile impl for RawFileDiskAio.
This marker supertrait requires DiskSize + Geometry + Sync,
all of which are now satisfied.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::Resizable trait implementation for
RawFileDiskAio. Calls file.set_len(size) and wraps the
I/O error in BlockError on failure.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::SparseCapable trait implementation for
RawFileDiskAio. Delegates to probe_sparse_support() to
detect whether the underlying file supports hole-punching.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::Geometry trait implementation for
RawFileDiskAio. Probes disk topology from the file,
falling back to defaults on failure. Takes &self instead
of &mut self and uses unwrap_or_else for cleaner error
handling.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::DiskFd trait implementation for
RawFileDiskAio. Delegates to file.as_raw_fd() via
BorrowedDiskFd, taking &self instead of &mut self.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::PhysicalSize trait implementation for
RawFileDiskAio. Returns the physical size from
query_device_size wrapped in BlockError on failure,
consistent with the DiskSize impl.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::DiskSize trait implementation for
RawFileDiskAio using BlockError and BlockResult. Takes
&self instead of &mut self.
Add BlockError, BlockErrorKind, BlockResult, and disk_file
imports needed by this and subsequent trait impls.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add #[derive(Debug)] to RawFileDiskAio. This is required
by the new disk_file traits which have Send + Debug bounds.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add a ramp time before measuring the block rate limiter tests so
both the single device and group workloads are measured after
warm up to make the measurements less sensitive to startup
transients.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
